code: def normalize_key(key: str):
      return key.replace(LBRACK, PERIOD).replace(RBRACK, "")
  
imports: import os
  import re
  import typing
  from collections.abc import Iterable, Mapping
  from functools import singledispatch
  from funcy import memoize, rpartial
  from dvc.exceptions import DvcException
  from dvc.utils.flatten import flatten
label_desc: Use image node_id 4 for calling a global function with example usage: normalize_key(key) and returns: key